Polycarbonates are well known thermoplastic materials which, due to their many advantageous properties, are used as thermoplastic engineering materials. The polycarbonates may generally be prepared by the reaction of a carbonate precursor such as phosgene with a dihydric phenol such as bisphenol-A. These polycarbonates exhibit, for example, excellent properties of toughness, flexibility, optical transparency, and high heat distortion temperatures. However, in certain applications better impact properties than those possessed by conventional polycarbonates are required. It is known that the impact properties of polycarbonates can be improved by blending with the polycarbonate resins certain impact modifiers. While the resultant compositions exhibit improved impact properties, the use of impact modifier additives suffers from several disadvantages. Among these disadvantages is the fact that some of these impact modifiers tend to adversely affect the optical properties, such as the transparency, of the polycarbonates. Another disadvantage lies in the fact that these compositions are blends of two different components thus resulting in the well known problems associated with multicomponent blends.
It would be very advantageous if polycarboncarbonates could be provided which exhibit improved impact properties as compared with conventional carbonate resins. It is, therefore, an object of the instant invention to provide carbonate resins exhibiting improved impact properties.